Herald and tribune. [volume] (Jonesborough, Tenn.) 1869-current, 1887-05-12
CHANGES OF COLOR.


HOW the Chameteon Nhrtc1 ks huo -
lt Accordance with Its Environments.
3 There Is tiny crustacean. the
chameleon shrimp. which can alter IT'S
hue to that Of any material on which 1t
happens to rest. On sandy bottom
1t appears gray or sand colored; when
lurking among sea-weed Il becomes
green, or red, or brown, according to
the nature Of its momentary back
ground. Probably the effect is quite
unconscious, or at least Involuntary.
like blushing with ourselves-and no
body ever bushes on purpose, though
they do say distinguished poet
once complained that an eminent
actor did not follow his stage direc-
tions because he omitted to obey the
rubrical remark: "Here Harold pur-
pies with anger" The change ispro-
duced by certain automatic muscles
which force up particular pigment
| cells above the others, green coming
to the top on green surface, red on a
ruddy one, and brown or gray where
the circumstances demand them.
Many kinds of fish similarly alter color
to suit their background by forcing
backward or forward certain special
| pigment cells known as chromato-
phores, whose various cobinations pro-
duce almost any required tone or
shade. Almost all reptiles and am
phibians possess the power of changing
their hue in accordance with their en-
vironment in very high degree; and
among certain tree toads and frogs it
Is difficult to say what is-the normal
coloring, as they vary indefinitely from
buff and dove-color TO chocolate-brown.
rose and even lilac. elg.1
! But of all the parti-colored reptiles
the chameleon is by far the best known,
and on the whole the most remarkable
for his Inconsistency for coloration. Like
a lacertine Vicar of Bray, he varies
incontinently from buff to blue, and
from blue back to orange again, under
stress Of circumstances. The mechan-
ism of this curious change is extremely
complex. Tiny corpuscles of different
pigments are sometimes hidden in the
depths of the chameleon's skin, and
sometimes spread out on its surface in
an interlacing network Of brown or
purple. In addition to this prime col
oring matter, however, the animal also
possesses normal yellow pigment,
and blush layer in the skin which
acts like the iridium glass so largely
employed, by DR.. Salyiati, being seen
as straw-colored with q trans
mitted light. but assuming faint lilac
tint against an opaque absorbent sur.
face. While sleeping the chameleon
, becomes almost white in the shade, but
: II light falls upon him he slowly dark
ems by an automatic process Gh'
movements of the corpusclel
III are governed pyopposite nerves ,a,,,
q muscles which either cause them t
: bury themselves under the true skin
d or to form an Opaque ground behin'
: the blue layer, or to spread out in
o ramifying mass on the outer surface
n and so produce as desired almost an.
o necessary shade of gray, green, blacl
or yellow 1t is an interesting fac
that many chrysalids undergo precisel.
similar changes Of color in adaptation
: to the background against which the.
d suspend themselves, being gray on
gray surface, green on q green one
It and even half red and half black whel
+ hung up against pieces Of parti-coloreC
J. paper.--Grant Allen. IN CornhW Mag
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